The white keys on a musical keyboard such as a MIDI keyboard play the standard 12-semitone scale (C Major music scale). The black keys play the sharps and flats of the music scale. There are different forms of scales playable on MIDI keyboards. All but the C major scale involve use of at least one of the black keys. Beginners sometimes find the use of the black keys difficult.
Also, pentatonic scales are often used in Asian music. The ability to easily play pentatonic scales exists in traditional ‘Asian’ instruments but not on MIDI keyboards. When a person with little music background plays on the 7-note white keys or black keys of a traditional 7-tone MIDI keyboard, it is very difficult for them to play rhythmic and nice-sounding music. Pentatonic instruments, with their five-note scale, are easy to play and learn. A person with little music background can quite easily play melodiously and rhythmically.
Also, on most MIDI keyboards each key has only one function—to play a designated, predetermined note. Function keys are provided to allow a user certain functionality when a particular function key is activated. Such function keys are limited in number.